#include <cstdio>
using namespace std;
int a[15][15];
int n;
int main()
{
    scanf("%d", &n);
    for (int i = 1; i <= n; i++)
    {
        a[i][1] = a[1][i] = 1;
    }
    for (int i = 2; i <= n; i++)
    {
        for (int j = 2; j <= n; j++)
        {
            a[i][j] = a[i - 1][j] + a[i][j - 1];
        }
    }
    printf("%d", a[n][n]);
    return 0;
}